github.com/ryanslade/nomad@v0.2.4-0.20160128061903-fc95782f2089/client/driver/env/env.go (about)

     1  package env
     2  
     3  import (
     4  	"fmt"
     5  	"strconv"
     6  	"strings"
     7  
     8  	hargs "github.com/hashicorp/nomad/helper/args"
     9  	"github.com/hashicorp/nomad/nomad/structs"
    10  )
    11  
    12  // A set of environment variables that are exported by each driver.
    13  const (
    14  	// The path to the alloc directory that is shared across tasks within a task
    15  	// group.
    16  	AllocDir = "NOMAD_ALLOC_DIR"
    17  
    18  	// The path to the tasks local directory where it can store data that is
    19  	// persisted to the alloc is removed.
    20  	TaskLocalDir = "NOMAD_TASK_DIR"
    21  
    22  	// The tasks memory limit in MBs.
    23  	MemLimit = "NOMAD_MEMORY_LIMIT"
    24  
    25  	// The tasks limit in MHz.
    26  	CpuLimit = "NOMAD_CPU_LIMIT"
    27  
    28  	// The IP address for the task.
    29  	TaskIP = "NOMAD_IP"
    30  
    31  	// Prefix for passing both dynamic and static port allocations to
    32  	// tasks.
    33  	// E.g. $NOMAD_PORT_1 or $NOMAD_PORT_http
    34  	PortPrefix = "NOMAD_PORT_"
    35  
    36  	// Prefix for passing task meta data.
    37  	MetaPrefix = "NOMAD_META_"
    38  )
    39  
    40  // The node values that can be interpreted.
    41  const (
    42  	nodeIdKey    = "node.unique.id"
    43  	nodeDcKey    = "node.datacenter"
    44  	nodeNameKey  = "node.unique.name"
    45  	nodeClassKey = "node.class"
    46  
    47  	// Prefixes used for lookups.
    48  	nodeAttributePrefix = "attr."
    49  	nodeMetaPrefix      = "meta."
    50  )
    51  
    52  // TaskEnvironment is used to expose information to a task via environment
    53  // variables and provide interpolation of Nomad variables.
    54  type TaskEnvironment struct {
    55  	env      map[string]string
    56  	meta     map[string]string
    57  	ports    map[string]int
    58  	allocDir string
    59  	taskDir  string
    60  	cpuLimit int
    61  	memLimit int
    62  	ip       string
    63  	node     *structs.Node
    64  
    65  	// taskEnv is the variables that will be set in the tasks environment
    66  	taskEnv map[string]string
    67  
    68  	// nodeValues is the values that are allowed for interprolation from the
    69  	// node.
    70  	nodeValues map[string]string
    71  }
    72  
    73  func NewTaskEnvironment(node *structs.Node) *TaskEnvironment {
    74  	return &TaskEnvironment{node: node}
    75  }
    76  
    77  // ParseAndReplace takes the user supplied args replaces any instance of an
    78  // environment variable or nomad variable in the args with the actual value.
    79  func (t *TaskEnvironment) ParseAndReplace(args []string) []string {
    80  	replaced := make([]string, len(args))
    81  	for i, arg := range args {
    82  		replaced[i] = hargs.ReplaceEnv(arg, t.taskEnv, t.nodeValues)
    83  	}
    84  
    85  	return replaced
    86  }
    87  
    88  // ReplaceEnv takes an arg and replaces all occurences of environment variables
    89  // and nomad variables.  If the variable is found in the passed map it is
    90  // replaced, otherwise the original string is returned.
    91  func (t *TaskEnvironment) ReplaceEnv(arg string) string {
    92  	return hargs.ReplaceEnv(arg, t.taskEnv, t.nodeValues)
    93  }
    94  
    95  // Build must be called after all the tasks environment values have been set.
    96  func (t *TaskEnvironment) Build() *TaskEnvironment {
    97  	t.nodeValues = make(map[string]string)
    98  	t.taskEnv = make(map[string]string)
    99  
   100  	// Build the task metadata
   101  	for k, v := range t.meta {
   102  		t.taskEnv[fmt.Sprintf("%s%s", MetaPrefix, strings.ToUpper(k))] = v
   103  	}
   104  
   105  	// Build the ports
   106  	for label, port := range t.ports {
   107  		t.taskEnv[fmt.Sprintf("%s%s", PortPrefix, label)] = strconv.Itoa(port)
   108  	}
   109  
   110  	// Build the directories
   111  	if t.allocDir != "" {
   112  		t.taskEnv[AllocDir] = t.allocDir
   113  	}
   114  	if t.taskDir != "" {
   115  		t.taskEnv[TaskLocalDir] = t.taskDir
   116  	}
   117  
   118  	// Build the resource limits
   119  	if t.memLimit != 0 {
   120  		t.taskEnv[MemLimit] = strconv.Itoa(t.memLimit)
   121  	}
   122  	if t.cpuLimit != 0 {
   123  		t.taskEnv[CpuLimit] = strconv.Itoa(t.cpuLimit)
   124  	}
   125  
   126  	// Build the IP
   127  	if t.ip != "" {
   128  		t.taskEnv[TaskIP] = t.ip
   129  	}
   130  
   131  	// Build the node
   132  	if t.node != nil {
   133  		// Set up the node values.
   134  		t.nodeValues[nodeIdKey] = t.node.ID
   135  		t.nodeValues[nodeDcKey] = t.node.Datacenter
   136  		t.nodeValues[nodeNameKey] = t.node.Name
   137  		t.nodeValues[nodeClassKey] = t.node.NodeClass
   138  
   139  		// Set up the attributes.
   140  		for k, v := range t.node.Attributes {
   141  			t.nodeValues[fmt.Sprintf("%s%s", nodeAttributePrefix, k)] = v
   142  		}
   143  
   144  		// Set up the meta.
   145  		for k, v := range t.node.Meta {
   146  			t.nodeValues[fmt.Sprintf("%s%s", nodeMetaPrefix, k)] = v
   147  		}
   148  	}
   149  
   150  	// Interpret the environment variables
   151  	interpreted := make(map[string]string, len(t.env))
   152  	for k, v := range t.env {
   153  		interpreted[k] = hargs.ReplaceEnv(v, t.nodeValues, t.taskEnv)
   154  	}
   155  
   156  	for k, v := range interpreted {
   157  		t.taskEnv[k] = v
   158  	}
   159  
   160  	return t
   161  }
   162  
   163  // EnvList returns a list of strings with NAME=value pairs.
   164  func (t *TaskEnvironment) EnvList() []string {
   165  	env := []string{}
   166  	for k, v := range t.taskEnv {
   167  		env = append(env, fmt.Sprintf("%s=%s", k, v))
   168  	}
   169  
   170  	return env
   171  }
   172  
   173  // EnvMap returns a copy of the tasks environment variables.
   174  func (t *TaskEnvironment) EnvMap() map[string]string {
   175  	m := make(map[string]string, len(t.taskEnv))
   176  	for k, v := range t.taskEnv {
   177  		m[k] = v
   178  	}
   179  
   180  	return m
   181  }
   182  
   183  // Builder methods to build the TaskEnvironment
   184  func (t *TaskEnvironment) SetAllocDir(dir string) *TaskEnvironment {
   185  	t.allocDir = dir
   186  	return t
   187  }
   188  
   189  func (t *TaskEnvironment) ClearAllocDir() *TaskEnvironment {
   190  	t.allocDir = ""
   191  	return t
   192  }
   193  
   194  func (t *TaskEnvironment) SetTaskLocalDir(dir string) *TaskEnvironment {
   195  	t.taskDir = dir
   196  	return t
   197  }
   198  
   199  func (t *TaskEnvironment) ClearTaskLocalDir() *TaskEnvironment {
   200  	t.taskDir = ""
   201  	return t
   202  }
   203  
   204  func (t *TaskEnvironment) SetMemLimit(limit int) *TaskEnvironment {
   205  	t.memLimit = limit
   206  	return t
   207  }
   208  
   209  func (t *TaskEnvironment) ClearMemLimit() *TaskEnvironment {
   210  	t.memLimit = 0
   211  	return t
   212  }
   213  
   214  func (t *TaskEnvironment) SetCpuLimit(limit int) *TaskEnvironment {
   215  	t.cpuLimit = limit
   216  	return t
   217  }
   218  
   219  func (t *TaskEnvironment) ClearCpuLimit() *TaskEnvironment {
   220  	t.cpuLimit = 0
   221  	return t
   222  }
   223  
   224  func (t *TaskEnvironment) SetTaskIp(ip string) *TaskEnvironment {
   225  	t.ip = ip
   226  	return t
   227  }
   228  
   229  func (t *TaskEnvironment) ClearTaskIp() *TaskEnvironment {
   230  	t.ip = ""
   231  	return t
   232  }
   233  
   234  // Takes a map of port labels to their port value.
   235  func (t *TaskEnvironment) SetPorts(ports map[string]int) *TaskEnvironment {
   236  	t.ports = ports
   237  	return t
   238  }
   239  
   240  func (t *TaskEnvironment) ClearPorts() *TaskEnvironment {
   241  	t.ports = nil
   242  	return t
   243  }
   244  
   245  // Takes a map of meta values to be passed to the task. The keys are capatilized
   246  // when the environent variable is set.
   247  func (t *TaskEnvironment) SetMeta(m map[string]string) *TaskEnvironment {
   248  	t.meta = m
   249  	return t
   250  }
   251  
   252  func (t *TaskEnvironment) ClearMeta() *TaskEnvironment {
   253  	t.meta = nil
   254  	return t
   255  }
   256  
   257  func (t *TaskEnvironment) SetEnvvars(m map[string]string) *TaskEnvironment {
   258  	t.env = m
   259  	return t
   260  }
   261  
   262  // Appends the given environment variables.
   263  func (t *TaskEnvironment) AppendEnvvars(m map[string]string) *TaskEnvironment {
   264  	if t.env == nil {
   265  		t.env = make(map[string]string, len(m))
   266  	}
   267  
   268  	for k, v := range m {
   269  		t.env[k] = v
   270  	}
   271  	return t
   272  }
   273  
   274  func (t *TaskEnvironment) ClearEnvvars() *TaskEnvironment {
   275  	t.env = nil
   276  	return t
   277  }